Process of chlorinating aromatic hydrocarbons including toluol.



C. ELLIS.

PROCESS OF CHLGRKNATlNG AROMATIC HYDROCARBONS INCLUDING TOLUOL.APPLICATION HLED FEB. 12, 1913. RENEWED NOV. 27, 1914.

1,146,142, Patented July 13, 1915.

Hal-

Warren/157s UNITED STATES PATENT OFFICE.

CABLETON ELLIS, OF KONTCLAIB, NEW JERSEY, ASSIGNOB TO CHADELOID CHEMICALCOMPANY, OF NEW YORK, N. Y., A CORPORATION OF WEST VIRGINIA.

PROCESS OF CHLOBINATING ABOMATIC HYDBOCABBONS INCLUDING TOLUOL.

Application filed February 12, 1918, Serial No. 747,848. RenewedNovember 27, 1914.

Yb all nlmm it may concern.

lie it knownthat I. Gama-iron ELLIS, a citizen of the United States. andresident of Montclair. Essex county, New Jersey, have made certain newand useful Inventions lielaiing nlatic Hydrocarbons Including'loluol, ofwhich the following is a specification, taken in connection with theaccompanying drawing, which forms part of the same.

These inventions relate especially to the chlorination of toluol in themanufacture of benzyl chlorid by the continuous circulation of an excessof toluol through the apparatus in which toluol vapor is produced andacted upon at high temperature by chlorin in the presence of a volatiletraveling catalyzer to promote side chain chlorination at a rapid rateunder the action of ultra-violet mercury light. for example, and thencondensing the benz vl chlorid and excess of toluol remaining to returnthe same to the apparatus while the h \'drochloric acid is substantiallyeliminated in gaseous condition. Of course by using an excess of chlorininstead of loluol nuclear chlorination is promoted, producinghr-nzal-ehiorid, benzo-trichlorid, cblor-lmizol and rhlor-toluol andother aromatic hydrocarlmns or other bodies may with advantage in many*ascs be chlorinated along similar lines.

In the accompanying drawing showing in a somewhat diagrammatic wayseveral illustrative forms of apparatus suitable for carrying out thisinvention, Figure 1 is a vertical section of one form of apparatus. Fig.2 is a horizontal section through the same along the line of Fig. 1.Fig. 3 is a vertical section of another form of conversion chamber: andFig. 4 is a section thereof along the line -li of Fig. 3.

The toluol may be vaporized in any desir d form of apparatus, such forexample, as the vaporizer or lash-pan 13 which may be suitably heatedinitially in any way as by steam or other heating means and which underworking conditions is heated by extending over a sutiicient portion ofthe upper surface of the conversion chamber 1 which maintained atsufiicient temperature to supply in large part at least the heat forvaporization in this way. The toluol is continuously or intermittentlysupplied to this vaporizer 28 by the valved inlet pipe 21 and thecatalyzing material preferably in Specification of Letters Patent.

to Processes of (hlorinating Aro-- Patented July 13, 1915.

Serial No. 874,380.

the form of phosphorous trichlorid or other catalytic material capableof traveling throughout the system in vaporous condition or otherwise,together with the toluol vapor, may also be supplied in desired amountsthrough the same inlet or otherwise. The vaporized toluol and catalyzerare discharged. through the vapor pipe 10 and connected inlet pipe 5into any suitable reaction or conversion chamber and are preferablymixed with the desired relatively small proportion of chlorin beforeentering the same, the chlorin if desired entering the vapor pipe 10through the chlorin inlet 11 so as to be substantially uniformly mixedwith the toluol in this way.

The conversion chamber may be of any desired form or construction so asto keep the vaporous material at the desired high temperature whiletraveling through the conversion chamber so as to secure as far aspossible uniformity of the desiredchlorination action which may beconsiderably promoted by exposing the vaporous reacting materials andintermixed traveling and substantially transparent catalyzer to theaction of ultra-violet light emitted from a cooperating mercury arclamp, for instance, which when operated at unusually high voltages, suchas 500 to 1000 volts or so, gives a large proportion of ultra-violetradiation which can be readily transmitted through the quartz glasswhich should be used for the lamp body and other partitions throughwhich this light-must pass.

The conversion chamber may be conveniently arranged in cylindrical formand provided with a substantially cylindrical outer casing, such as 1,and an inner substantially cylindrical casing 2 which may with advantagebe formed in whole or part of quartz glass, both of which casings may besecured in any desired way with the top and bottom membersof theconversion chamber. In order to promote the conversion action on thevaporized charge within the chamber suitable substantially radialpartitions may with advantage be arranged within the chamber, leavingspaces or passages 25, 26 alternately adjacent the outer and centralportions, as indicated in Fig. 2, so as to guide the material enteringthe vapor inletpipe 5 adjacent the separating partition 22 along thestaggered path indicated by the arrows past this series of inner andouter partitions 23, 24 until the material has passed part way orcompletely around the conversion chamber so as to be discharged from oneor more vapor outlets such as 6. These partitions may be convenientlymade of glass and the entire conversion chamber should of course belined either with glass or with some other suitable materialsufliciently resistant to the vapors so as not to undesirably rear-ttherewith or at least be free from objectionable reaction products. Oneor more ultra-violet lights, such as the high potential mercury light 4may be arranged within the lighting chamber 3 inside the inner casing soas to promote the desired side chain chlorinating action of the chlorinon part of the toluol vapor which is preferably present to the extent ofseveral times the quantity required to react with the chlorin supplied.For good results the chlorin need only be supplied to the extentrequired to react with 25 to 50 per cent. of the toluol passing throughthe system. This desired side chain chlorination is also promoted andthe rapidity of the reaction greatly increased by maintaining thevaporous charge. at high temperatures, between about 180 and 220 C. forinstance, giving desirable results, the upper temperature limit beingthat at which undesirable disintegration of the toluol or formation oftar or other undesirable products therefrom begins to take place. Thelower temperature limit is the condensing temperature of the benzylchlorid or other reaction components or products, although it isdesirable to keep the conversion chamber considerably above this pointfor most eflicient and rapid results. The conversion chamber or gaseouscharge fed thereto may be heated in any desired way and as indicated asuitable heater 7 may be arranged below the conversion chamber so as toheat the same by superheated steam or other gaseous material suppliedthereto through suitable pipes, such as 8, and it is of courseunderstood that the outer casing of this conversion chamber may beformed of special thickness or material as to minimize diffusion of heattherefrom, heavy lagging being desirable for this purpose in many cases.The vaporous charge may also be heated before entering the con-' versionchamber by heat'interchangers of any desired character such asdiagrammatically illustrated in Fig. 1 where the vapor pipe 10 is shownas passing through the enlarged heat interchanging jacket 9 with whichthe vapor outlet pipe 6 communicates so that the incoming vapor isheated by the hot outgoing or discharge vapors which are then carried bythe pipe 12 to "the dephlegmator 14 where theyare allowed to coolsufficiently to condense substantially all the benzyl chlorid and otherdesirable chlorinated products, such as the relatively'small proportionof benzal chlorid which may be produced, especially when the conversiontakes place at relatively lower temperatures. The benzyl chlorid and soforth may be allowed to escape from the dephlegmator through thedischarge pipe 15 and the remaining vaporous material may pass throughthe pipe 16 into any suitable condenser illustrated as 17 where thetemperature is sufiiciently reduced to condense the toluol andcat'alyzer which are separated by the trap or separator 18 and returnedthrough the pipe 20 to the vaporizer 13 while the hydrochloric acid gaswhich is a by-product of the reaction is discharged in l gaseouscondition through the pipe 19 for utilization in any desired way. Inthis way it will be seen that the phosphorous trichlorid catalyzer invaporous condition is intermixed with the vaporized toluol throughoutits passage through the conversion chamber so as to be fully effectivein promoting the desired chlorination and the excess of toluolpresentseems to be beneficial in preventing the catalyzer from becomingconverted into higher chlorids which appear to be less suitable, evenaside from their relatively less volatile character.

Figs. 3 and 4 show another form of conversion chamber in which the outercasing 27 may also be cylindrical and in which the inner casing 2 ofquartz glass or the like may be arranged to provide an inner chamber orpassage 3 for suitable ultra-violet mercury lights 4 or other suitablelights, such as high power carbon electrode are lights which may also beused with good results in some cases. In this instance the conversionchamber is provided with a separating partition 32 extending between theouter and inner casings so as to substantially prevent passage of thevaporous charge directly from the inlet 5 to the outlet 6 and the otherpartitions 28, 30 may as indicated extend all the way from the centralto the outer casings, but be provided with openings 29, 31alternately'at the top and bottom of the conversion chamber so as toguide the charge up and down through this staggered passage and effectits substantially uniform conversion.

This invention has been described in connection with a number ofillustrative forms of apparatus, parts, arrangements, materials,proportions, temperatures and treating conditions and agents, to thedetails of which disclosure the invention is not of course to belimited, since \Vhat is claimed is:

1. The process ofmaking benzyl' chlorid which comprises continuouslyvaporizing toluol and phosphorous trichlorid, in continuously supplyingchlorin gas to said vapors in amounts suflicient to combine with betweenabout 25 and 50 per cent. of said toluol 'vapor, in maintain" said mixedvaporous charge of toluol, ch orin and incorporated substantiallytransparent. catalyzer at temperatures between about 180- C. and

220 C. and in simultaneously passing said heated vaporized chargethrough staggered passages while subjecting the same to the action ofultra-violet light to form benzyl chlorid and hydrochloric acid, inheating the incoming charge by the converted hot tinuously supplyingchlorin gas to said vars in amounts sufficient to combine with tweenabout 25 and per cent. of said toluol vapor, in maintaining said mixedvaporous charge of toluol, chlorin and incorporated substantiallytransparent catalyzer at temperatures between about 180 C. and 220 C.while subjecting the same to the action of ultra-violet light to formbenzyl chlorid and hydrocloric acid, in condensing and separating benzylchlorid from the con verted vaporous charge, in condensing andseparating therefrom toluol and catalyzer and returning the same forfurther vaporization and treatment, in separating and discharginghydrochloric acid and in continuously supplying additional toluol to thecondensed toluol before again vaporizing the same.

3. The process of making benzyl chlorid which comprises continuouslyvaporizing toluol and phosphorous trichlorid, in continuously supplyingchlorin gas to said vapors in amounts sufficient to combine with betweenabout and 50 per cent. of said toluol vapor. in maintaining said mixedvaporous charge of toluol, chlorin and incorporated substantiallytransparent catalyzer at temperatures between about 180 C. and the pointof undesirable heat decomposition of the toluol and tar formationtherefrom While subjecting the same to the action of ultra-violet lightto form benzyl chlorid and hydrocloric acid, in condensing andseparating benzyl chlorid from the converted vaporous charge, incondensing and separating therefrom toluol and catalyzer and returningthe same for further vaporization and treatment, in separating anddischarging hydrochloric acid and in continuously supplying additionaltoluol to the condensed toluol before again vaporizing the same.

4. The process of making benzyl chlorid which comprises va toluol andphosphorous trichlori ,in supplyin chlorin gas to said vapors in amountssu 'cient to combine with only a portion of said toluol vapor, inmaintaining said mixed vaporous charge of toluol, chlorin andincorporated substantially transparent catalyzer at temperatures betweenabout180 C. and the point of undesirable heat decomposition of thetoluol and tar formation therefrom while subjecting the same to theaction of ultraviolet light to form benzyl chlorid and hydrochloricacid, in condensing and separating benzyl chlorid from the convertedvaporous charge, in condensing and separating therefrom toluol andcatalyzer and returning the same for further vaporization and treatment,in separating and discharging hydrochloric acid and in supplying ad-'ditional toluol to the condensed toluol before again vaporizing thesame.

5. The process of chlorinating aromatic hydrocarbons including toluolWhich comprises continuously vaporizing the hydrocarbon and volatilephosphorous trichlorid catalyzer, in continuously supplying chlorin gasto said vapors in amounts suflicient to combine with only a portion ofsaid bydrocarbon vapor, in maintaining said mixed vaporous charge ofhydrocarbon, chlorin and incorporated substantially transparentcatalyzer at temperatures between about 200 C. and the temperature ofundesirable heat decomposition and tar formation of the hydrocarbons andin simultaneously passing said heated vaporized charge through staggeredpassages while subjecting the same to the action of ultra-violet lightto form chlorinated hydrocarbon and hydrochloric acid, in heating theincoming charge by the converted hot outgoing charge, in condensing andseparating chlorinated hydrocarbon from the converted vaporous charge,in condensing and separating chlorinated hydrocarbon from the convertedvaporous charge, in condensing and separating therefrom unchlorinatedhydrocarbon and catalyzer and returning the same for furthervaporization and treatment and in separating and discharginghydrochloric acid and in continuously supplying additional hydrocarbonbefore again vaporizing the same.

6. The process of chlorinating aromatic hydrocarbon Which comprisesvaporizing the hydrocarbon and volatile phosphorous trichloridcatalyzer, in supplying chlorin gas to said vapors in amounts sufficientto combine With only a portion of said hydrocarbon vapor, in maintainingsaid mixed vaporous charge of hydrocarbon, chlorin. and incorporatedsubstantially transparent catalyzer at temperatures between about 200 C.and the temperature of undesirable heat decomposition and tar formationof the hydrocarbon while subjecting the same to the action ofultra-violet'hght to -form chlorinated hydrocarbon and hydrochloricacid, in condensing and separating chlorinated hydrocarbon from theconverted vaporous charge, in condensing and se arating therefromunchlorinated hydrocar on and catalyzer and returning the same forfurther vaporization and treatment and in separating and discharginghydrochloric acid and in supplying additional hydrocarbon before againvaporizing the same;

. 7 The process of chlorinating aromatic hydrocarbon which comprisesvaporizing the hydrocarbon and volatile catalyzer, in supplying chloringas to said vapors in amounts sufficient to combine with only a portionof said hydrocarbon vapor, in maintaining said mixed vaporous charge ofhydrocarbon, chlorin and incorporated substantially transparentcatalyzer at temperatures between the vaporizing temperatures of saidcatalyzer and the chlorinated hydrocarbon products formed and thetemperature of undesirable heat decomposition and tar formation of thehydrocarbon while subjecting the same to the action of ultra-violetchloric acid and in supplying additional hydrocarbon before againvaporizing the.

same.

8. The process of chlorinating aromatic hydrocarbons which comprisescontinuously vaporizing the hydrocarbon and .volatile catalyzer, incontinuously supplying chlorin gas to said vapors in amounts sufiicientto combine with only a portion of said hydro-- carbon vapor, inmaintaining said mixed vaporous charge of hydrocarbon, chlorin andincorporated substantially transparent -catalyzer at temperatures abovethe Vaporizing temperatures of said catalyzer and of the chlorinatedhydrocarbon product formed and below the temperature of tar formation,and undesirable heat decomposition of the hydrocarbon and insimultaneously feeding said heated vaporized charge forward whileconverting the same to form chlorinated hydrocarbon by the action ofultra-violet light, in heating the incoming charge by the converted hotoutgoing charge, in separating chlorinated hydrocarbon from theconverted vaporous charge, and in separating therefrom unconvertedhydrocarbon and cata-' lyzer and returning the same for furthervaporization and treatment.

9. The process of chlorinating aromatic hydrocarbons which comprisescontinuously vaporizing the hydrocarbon and volatile catalyzer, incontinuously supplyin chlorin gas to said vapors in amounts su cient tocombine with only a portion of said hydrocarbon vapor, in maintainingsaid mixed vaporous charge of hydrocarbon, chlorin and incorporatedsubstantially transparent catalyzer at temperatures above the vaporizingtemperatures of said catalyzer and of the chlorinated hydrocarbonproduct formed and below the temperature of tar formation andundesirable heatdecomposition of the,

hydrocarbon and in simultaneously feeding said heated vaporized chargeforward while converting the same to form chlorinated hydrocarbon by theaction of light, in separating chlorinated hydrocarbon fromthe convertedvaporous charge, and in separating therefrom unconverted hydrocarbon andcatalyzer and returning the same for further vaporization and treatment.

10. The process of chlorinating aromatic hydrocarbons which comprisescontinuously vaporizing the hydrocarbon and volatile catalyzer, incontinuously supplying chlorin gas to said vapors, in maintaining saidmixed vaporous charge of hydrocarbon, chlorin and incorporatedsubstantially transparent catalyzer at temperatures above the vaporizingtemperatures of said catalyzer and of the chlorinated hydrocarbonproduct formed and below the temperature of tar formation andundesirable heat decomposition of the hydrocarbon, and in simultaneouslyfeeding said heated vaporized charge forward while converting the sameto form chlorinated hydrocarbon, in separating chlorinated hydrocarbonfrom the converted vaporous charge, and in separating therefromunconverted hydrocarbon and catalyzer and returning the same for furthervaporization and treatment.

11. The process of chlorinating aromatic hydrocarbons whichcomprisesvaporizing the hydrocarbon and volatile catalyzer, in supplyingchlorin gas to said vapors, in maintaining said mixed vaporous charge ofhydrocarbon, chlorin and incorporated substantially transparentcatalyzer at temperatures above the vaporizing temperatures of saidcatalyzer and of the chlorinated hydrocarbon product formed and belowthe temperature of tar formation and undesirable heat decomposition ofthe hydrocarbon, and in simultaneously feeding said heated vaporizedcharge forward while converting the same to form chlorinatedhydrocarbon, in separating chlorinated hydrocarbon from the convertedvaporous charge, and in separating therefrom unconverted hydrocarbon andcatalyzer and returning the same for further vaporization and treatment.

12. The process of chlorinating aromatic hydrocarbons which comprisesvaporizing the hydrocarbon and incorporating, therewith volatilesubstantially transparent catalyzer, in incorporating chlorin with saidvapors and in feeding forward said mixed vaporous charge of hydrocarbon,chlorrn and incorporated catalyze]: and subjecting the same to highconversion temperatures while forming chlorinated hydrocarbon and inseparating the chlorinated hydrocarbon from the converted vaporouscharge.

13. The process of chlorinating aromatic hydrocarbons which comprisesfeeding forward a mixture of chlorin and hydrocarbon vapor andincorporated vaporous catalyzer and subjecting the vaporous mixture to atemperature substantially above the point of vaporization of theresulting chlorinated product while conversion takes place.

14. The process of chlorinating aromatic hydrocarbons which comprisesfeeding forward a mixture of chlorin and hydrocarbon vapor andsubjecting the vaporous mixture to a temperature substantially above thepoint of vaporization of the resulting chlorinated products whilecowsersion takes place.-

CARLETON ELLIS.

\Vitnesses:

llmmv L. DUNCAN, Jnssm B. KAY.

